There are many situations in which a person, such as a hospitalized patient is unable to excrete waste products in a bathroom. Unconscious patients, paraplegics, some post-operative patients and incontinent patients all require means to continuously or semi-continuously remove urine without leakage thereof and risk of urinary tract infections (UTIs).
Many different types of urinary catheters have been devised to effectively remove urine from patients. For example:
GB1426429A, assigned to Simpla Plastics, describes a urinary collection apparatus comprising a collection bag and a tube connected at one end to the bag and having a connector cap for connection to a catheter at its other end, the tube comprising at least a portion which is of a material which is self-sealing when punctured by an instrument e.g. a hypodermic syringe, for withdrawing a sample of urine. The portion may comprise a sleeve of butadiene concentric with, and closely gripping the tube. The portion may form an integral part of the tube or the whole tube may be covered by a butadiene or an other self-sealing sleeve. The bag is provided with a drainage valve as disclosed in GB1310581 and has a one-way inlet valve. A graduated scale is provided on one face of the bag.
U.S. Pat. No. 3,861,396A to Bruckner describes means for eliminating a negative pressure problem, e.g. in a closed urinary system comprising a catheter, a downwardly extending tube and a collection bag. The tube has an internal coating of a hydrophilic polymer, preferably a 2-hydroxyethyl methacrylate polymer, or can be made completely of the hydrophilic polymer.
Bruckner describes there being a major problem with these systems, which is the build-up of negative pressures in the bladder for example, due to the build-up of the fluids columns in the various cannulae (lumens), e.g. see Vaillancourt U.S. Pat. No. 3,583,401.
This build-up is due to a combination of: a) closed system—which precludes the influence of atmospheric pressures which would break this column, and b) the surface tension of the tubing which acts to hold or retain the fluid in the tube.
Methods currently used to overcome this problem include: large bore drain tubing and the placing of a vent in the catheter connector. The former solution suffers from the limitation that the product is bulky and difficult to work with, whereas the latter has been demonstrated to only work for a very short period of time before the filter element gets clogged due to infestations, and/or hydrostatic pressures. The disclosure of '396 is concerned with a novel method which allows for the use of smaller bore tubing, as well as functioning over the life of the drainage system.
Briefly, '396 is concerned with using a hydrophilic tubing having an internal diameter of at least 0.2 inch to prevent capillary action as the connecting member (drainage tube) between the cannulae and collector. It has been found that a hydrophilic tube (having water-wetting properties) will not support a column of fluid even though a vacuum may be applied at one end.
U.S. Pat. No. 3,902,492, to Greenhalgh, describes a catheter for the continuous irrigation of the bladder which has a drainage tube for the removal of fluid from the bladder, an auxiliary axial bore extending through the wall of the drainage tube, and an irrigation tube extending from the axial bore beyond the tip of the catheter. The irrigation tube has a plurality of radial discharge outlets. During use, the irrigation tube curves around the bladder; fluid passes through the irrigation tube to provide a discharge spray and a turbulent flow of liquid in the bladder. This provides for a peripheral bladder irrigation which is an improvement over a single discharge point near the entry of a catheter into a bladder. The catheter also preferably has a second axial bore in its wall which terminates in an opening beneath a sheath of expandable material which can be inflated by fluid applied under pressure through the second axial bore, to secure the catheter in place.
U.S. Pat. No. 6,045,542, to Cawood et al., describes a urine collection bag having the basic features appearing in U.S. Pat. No. 4,449,971. The bag also includes an improvement in the form of an extendable drain tube that is normally retracted and retained in flat coiled condition against the front wall of the bag. The tube is biased into its coiled condition by the elastic memory of the thermoplastic material from which it is formed and, in a preferred embodiment, the flat coil is oval-shaped with its major axis extending generally vertically when the bag is worn. A retention strap attached to the front wall of the bag serves to hold the drain tube in its coiled condition against the bag's front wall. A valve is located at a distal end of the drain tube, which is used to control drainage. The location of the valve prevents spillage of residual urine upon recoil of the drain tube.
U.S. Pat. No. 7,094,220 to Tanghoj et al, describes a catheter assembly allowing for non-contaminated insertion of a catheter into a urinary canal. The assembly includes a package for the catheter and an applicator to be used for guiding the catheter into the urinary canal without touching the catheter by holding the catheter via walls of the applicator. The assembly further comprises clamping means for pressing the walls of the applicator into engagement with the catheter. The present invention further relates to an applicator with integrated clamping means to be used with the assembly.
The catheter or at least a section thereof may be provided with a hydrophilic surface. When treated with a liquid swelling medium, such a surface will provide an excellent lubrication for the insertion and also provide compatibility with the body tissue.
US2006189962A to Burtoft, describes a urinary drainage bag for draining urine from the navel as a result of a urinary diversion. The means include a urine collection bag, a reflux chamber attached to the collection bag for accommodating urine backflow and working out bubbles, a multi-size catheter tip extending upwardly from the reflux chamber for attachment to a transfer or catheter tube, a urine discharge opening adjacent the lower end of the collection bag for draining urine from the collection bag, and a fluid measurement scale imprinted on the front of the collection bag for measuring the amount of urine held within the urine collection bag.
The urinary drainage bag also includes a tether adjacent the upper end of the collection bag for conveniently hanging the collection bag, and a handle and mounting hook are also attached to the upper end of the collection bag for supporting the urinary drainage bag on a bed railing.
Thus, as will be noted from the publications hereinabove, the current state of the art is to use a catheter having at least part of the tubing thereof comprising a hydrophilic surface. Additionally, some of these publications relate to the negative pressure in the bladder, due to the build-up of the fluids columns in the various cannulae (lumens) as being a problem, which U.S. Pat. No. 3,861,396 sought to overcome.
It is to be noted, and as will be discussed hereinafter with regard to comparative FIGS. 1 and 2 relating to prior art arrangements, that there are still several major problems with the prior art arrangements which result in infection in catheterized patients both during catheterization and during the changing of the catheter arrangement.
Thus there is still a need to provide inexpensive, versatile urinary catheters, which allow for use over long periods of time with reduced risk of UTI.
Therefore, it is an object of some aspects of the present invention to provide hygienic systems and methods for collecting urine from a patient.
In preferred embodiments of the present invention, improved methods and novel apparatus are provided for collection of urine whereby the collection unit remains sterile throughout the collection time.
In other preferred embodiments of the present invention, a method and system are described for removing urine, under a constantly negative pressure, from a patient.